Many commercial products are produced using chemical as well as biological processes. Pharmaceuticals, for example, are produced in commercial quantities using scaled-up reactors and other equipment. So-called biologics are drugs or other compounds that are produced or isolated from living entities such as cells or tissue. Biologics can be composed of proteins, nucleic acids, or complex combinations of these substances. They may even include living entities such as cells. In order to produce biologics on a commercial scale, sophisticated and expensive equipment is needed. In both pharmaceutical and biologics, for example, various processes need to occur before the final product is obtained. For example, in the case of biologics, cells may be grown in a growth chamber or the like and nutrients may need to be carefully modulated into the growth chamber. Waste products produced by cells may also have to be removed on a controlled basis from the fermentation chamber. As another example, biologic products produced by living cells or other organisms may need to be extracted and concentrated. This process may involve a variety of filtration and separation techniques.
Because there are a number of individual processes required to be produce the final product, various reactants, solutions, and washes are often pumped or otherwise transported to various subsystems using conduits and associated valves. These systems may be quite cumbersome and organizationally complex due to the large numbers of conduits, valves, sensors, and the like that may be needed in such systems. Not only are these systems visually complex (e.g., resembling spaghetti) they also include many components that are required to be sterilized between uses to avoid cross-contamination issues. Indeed, the case of drug and biologic preparation, the Federal Food and Drug Administration (FDA) is becoming increasingly strict on cleaning, sterilization or bio-burden reduction procedures that are required for drug and pharmaceutical preparations. This is particularly a concern because many of these products are produced in batches which would require repeated cleaning, sterilization or bio-burden reduction activities on a variety of components.
More recently, disposable solutions have been proposed that utilize flexible (e.g., silicone) tubing during the manufacturing process. The flexible tubing may be discarded after use and replaced with new tubing, thereby avoiding the need to sterilize some or all of the equipment. For valve operations, the flexible tubing is placed inside a two-piece valve and a valve actuator is used to selectively pinch the flexible tubing. The valve is closed when the flexible tubing is pinched shut by the valve actuator and open when the actuator leaves the flexible tubing in the resting, open state. Often these valves need to interface with or connect to other process operations. In many pharmaceutical or bioprocess applications, particular process operations may require that fluid flow be reversed. In such situations, like when a chromatography column is used, this may require a large number of separate valves and conduits to accomplish the desired flow reversal. There thus is a need for a more elegant and compact solution to reverse flow that also incorporates the benefits of using flexible, disposable tubing.